Phase II trial to study the effectiveness of bevacizumab combined with vinorelbine in treating patients who have stage IV breast cancer. Monoclonal antibodies such as bevacizumab can locate tumor cells and either kill them or deliver tumor-killing substances to them without harming normal cells. Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining monoclonal antibody with chemotherapy may kill more cancer cells